title: 17β-Estradiol and estradiol fatty acyl esters and estrogen-converting enzyme expression in adipose tissue in obese men and women.
abstract: BACKGROUND
  Obesity is associated with increased circulating 17β-estradiol (E₂), but less is known about E₂ concentrations in adipose tissue. In addition to E₂, adipose tissue synthesizes E₂ fatty acyl esters (E₂-FAE).
  
  
  OBJECTIVE
  The aim was to compare estrogen concentrations and expression of estrogen-converting enzymes in adipose tissue between severely obese men and women.
  
  
  METHODS
  Tissue samples were obtained during elective surgery in University Central Hospital in the years 2008 through 2011.
  
  
  METHODS
  We studied 14 men and 22 premenopausal women undergoing bariatric surgery and 10 control women operated for nonmalignant reasons.
  
  
  METHODS
  Paired samples were taken from abdominal sc and visceral adipose tissue and serum and analyzed for E₂ and E₂-FAE by fluoroimmunoassay and liquid chromatography-tandem mass spectrometry. mRNA expression of genes was analyzed by quantitative PCR.
  
  
  RESULTS
  Compared with men, E₂ levels in sc adipose tissue in obese women were higher, along with higher relative mRNA expression of steroid sulfatase and 17β-hydroxysteroid dehydrogenases 1, 7, and 12. In men, E₂-FAE concentrations in adipose tissue were similar to E₂ but in women significantly lower compared with E₂. Adipose tissue E₂-FAE and serum E₂-FAE levels correlated positively in obese subjects. Serum E₂ did not significantly correlate with E₂ concentration or mRNA expression of genes in adipose tissue in obese men or women.
  
  
  CONCLUSIONS
  The production of E₂ by the large adipose mass was not reflected by increased circulating E₂ concentrations in severely obese men or women. However, adipose tissue may contribute to concentrations of serum E₂-FAE.
authors.affiliation: Folkhälsan Research Center, Biomedicum Helsinki C415, Haartmaninkatu 8, 00290 Helsinki, Finland. veera.vihma@hus.fi.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Veera
authors.initials: V
authors.lastname: Vihma
authors.forename: Jarkko
authors.initials: J
authors.lastname: Soronen
authors.forename: Ursula
authors.initials: U
authors.lastname: Turpeinen
authors.forename: Esa
authors.initials: E
authors.lastname: Hämäläinen
authors.forename: Hanna
authors.initials: H
authors.lastname: Savolainen-Peltonen
authors.forename: Tomi S
authors.initials: TS
authors.lastname: Mikkola
authors.forename: Jussi
authors.initials: J
authors.lastname: Naukkarinen
authors.forename: Kirsi H
authors.initials: KH
authors.lastname: Pietiläinen
authors.forename: Matti
authors.initials: M
authors.lastname: Jauhiainen
authors.forename: Hannele
authors.initials: H
authors.lastname: Yki-Järvinen
authors.forename: Matti J
authors.initials: MJ
authors.lastname: Tikkanen
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D000215:Acylation; D000328:Adult; D015992:Body Mass Index; D004958:Estradiol / Q000031:analogs & derivatives / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D005227:Fatty Acids / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D050152:Intra-Abdominal Fat / Q000201:enzymology / Q000378:metabolism*; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000378:metabolism* / Q000601:surgery; D012333:RNA, Messenger / Q000378:metabolism; D012727:Sex Characteristics; D013237:Stereoisomerism; D043266:Steryl-Sulfatase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D050507:Subcutaneous Fat, Abdominal / Q000201:enzymology / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D007527:Isoenzymes; D012333:RNA, Messenger; D004958:Estradiol; D015067:17-Hydroxysteroid Dehydrogenases; C584039:STS protein, human; D043266:Steryl-Sulfatase